Fix apparatus of an electric-photograpic printer

专利摘要:
In the fixing apparatus of the electrophotographic image forming apparatus according to the present invention, after developing the electrostatic latent image formed on the photoconductor according to the control signal of the control device, the developer forming the image is transferred onto printing paper, and the developer of the transferred image is opened. And a fixing roller for fixing the developer transferred to the printing paper by heat radiated from a heat source assembled therein, the cylindrical roller being fixed to the printing paper by pressing force. It is installed on the lower side of the fixing roller to rotate opposite to the fixing roller and presses the printing paper against the fixing roller to press the developer transferred to the printing paper and to support the shaft of the pressing roller at both ends. Pressing means for generating a pressing force for the pressing roller to press the fixing roller and the control Depending on the value signal is characterized in that it comprises a pressing force varying means for varying a pressing force of said pressing means at a predetermined cycle. According to the present invention, a small amount of solenoid is used, and power consumption is low, but wrinkles do not occur when printing an envelope.
公开号:KR20030043135A
申请号:KR1020010074153
申请日:2001-11-27
公开日:2003-06-02
发明作者:박서원
申请人:삼성전자주식회사；
IPC主号:

专利说明:

Fixing apparatus for an electrophotographic image forming apparatus
[14] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly, to a fixing apparatus for an electrophotographic image forming apparatus in which pressing force is varied according to the type of printing paper.
[15] In general, an electrophotographic image forming machine scans a laser beam on a photosensitive member charged with high voltage to form an electrostatic latent image, and develops the electrostatic latent image as a visible image with a developer supplied by a developing apparatus, and transfers it to printing paper. After printing, the printing apparatus is used to fix a developer, which forms an image transferred to printing paper, with a predetermined heat and pressure, and to perform printing, such as a laser printer, a copying machine, a facsimile, or the like.
[16] However, in order to obtain a good quality image without wrinkles on the printing paper in the fixing process, appropriate heat of fixing and fixing pressure are required according to the type of printing paper. If an image transferred to a relatively thick bag is fixed by a fixing device set to apply proper fixing heat and fixing pressure to a plain paper, wrinkles may occur in the bag.
[17] Therefore, in order to print several types of printing paper with one electrophotographic image forming machine, it is necessary to vary the fixing pressure of the fixing device according to the type of printing paper. To this end, many means have been taken so far, and an example thereof is shown in FIG. 1.
[18] Referring to FIG. 1, the fixing apparatus of the conventional electrophotographic image forming apparatus includes a fixing roller 2, a pressure roller 3, a pressure spring 5, and a pressing force adjusting means 7.
[19] The fixing roller 2 is a cylindrical roller provided in the main body 4 of the electrophotographic image forming machine, and a heat source such as a halogen lamp is assembled therein. The fixing roller 2 is made of a material having good thermal conductivity, and melts a developer that is transferred to the printing paper 1 by heat radiated from a heat source to form an image.
[20] The pressing roller 3 is installed to rotate opposite to the fixing roller 2 at the lower side of the fixing roller 2, and both ends of the pressing roller shaft 3a are supported upward by the pressing spring 5.
[21] The pressing spring 5 supports both ends of the pressing roller shaft 3a upward to apply a pressing force between the pressing roller 3 and the fixing roller 2, and is provided on both upper sides of the fixing member 6.
[22] The pressing force adjusting means 7 adjusts the pressing force between the fixing roller 2 and the pressing roller 3, and is composed of the solenoid 9 and the movable plate 8. The movable plate 8 is assembled below the central part of the fixing member 6, and the solenoid 9 operates the movable plate 8 up and down in accordance with a control signal of a control device (not shown). That is, when the movable plate 8 is located on the upper side, the pressure spring 5 is compressed to increase the pressing force of the pressure roller 3, and when the movable plate 8 is located on the lower side, the compression of the pressure spring 5 is partially. The pressure is applied to the pressure roller 3 to be eliminated.
[23] An operation according to the type of printing paper of the fixing apparatus of the conventional electrophotographic image forming apparatus having the above configuration will be described.
[24] First, in the case of printing on general paper, a relatively high fixing pressure is required, so that the movable plate 8 of the pressing force adjusting means 7 should be located above. Therefore, when the user selects the general paper, the control device of the electrophotographic image forming machine checks the position of the movable plate 8 of the pressing force adjusting means 7. If the movable plate 8 is located on the upper side, the printing paper is supplied and printed as it is. If the movable plate 8 is located on the lower side, the solenoid 9 is operated so that the movable plate 8 is located on the upper side. .
[25] On the contrary, when printing a thick printing paper such as an envelope, a relatively low fixing pressure is required as compared with the case of general paper, so that the movable plate 8 of the pressing force adjusting means 7 should be located at the lower side. Therefore, when the bag is selected, the control device of the image forming machine checks whether the movable plate 8 of the pressing force adjusting means 7 is located below. If it is on the upper side, the solenoid 9 is operated to position the movable plate 8 to the lower side.
[26] Here, a process in which the pressing force for pressing the fixing roller 2 by the pressing roller 3 by the solenoid 9 is variable will be described as follows.
[27] When the movable plate 8 of the pressing force adjusting means 7 is located on the upper side, when the solenoid 9 is operated, the movable plate 8 moves downward in the gravity direction.
[28] When the movable plate 8 is moved downward, the fixing member 6 assembled on the upper side of the movable plate 8 moves downward together with the movable plate 8. Therefore, when the fixing member 6 moves downward, the distance between the pressing roller shaft 3a and the fixing member 6 is widened, so that the force of the pressing spring 5 to press the pressing roller shaft 3a is reduced. Done.
[29] On the contrary, when the movable plate 8 is located on the upper side, the interval between the press roller shaft 3a and the fixing member 6 is narrowed, so that the force of the press spring 5 to press the press roller shaft 3a is increased.
[30] Therefore, when printing is performed after setting the proper pressing force according to the type of printing paper 1, the image transferred from the developing apparatus is applied to the printing paper 1 by the heat of the fixing roller 2 and the pressing pressure of the pressing roller 3. The transferred developer is fixed and wrinkles of printing paper do not occur.
[31] However, in the above-described fixing apparatus of the electrophotographic image forming apparatus, the fixing member 6 must be moved up and down as a whole in order to adjust the force that the pressing spring 5 presses the pressing roller 3. That is, since the solenoid 9 has to move all of the pressure roller 3 and the pressure spring 5 installed on the fixing member 6 up and down, there is a problem that a large capacity solenoid is required and power consumption is also large.
[32] The present invention has been made to solve the above problems, by using a small capacity of the solenoid to change the pressing force according to the type of printing paper, so that the wrinkles do not occur in the printing paper during fixing, the electronic power consumption is less It is an object of the present invention to provide a fixing device for a photographic image forming machine.
[1] 1 is a conceptual diagram showing a fixing apparatus of a conventional electrophotographic image forming apparatus;
[2] 2 is a front view schematically showing a fixing apparatus of an electrophotographic image forming apparatus according to the present invention;
[3] 3 is a side cross-sectional view of the fixing device of the electrophotographic image forming apparatus of FIG. 2 seen from A-A;
[4] FIG. 4 is a view showing a state in which the gear cam rotates and starts to engage with the fixing gear in FIG. 3.
[5] * Description of the symbols for the main parts of the drawings *
[6] One; Printing paper 101; Fixing Roller
[7] 102; Fixing gear 103; Press Roller
[8] 110; Pressing means 111; housing
[9] 112; Elastic member 121; Platen
[10] 122; Gear part 123; Cam
[11] 124; Gear cam 125; wait
[12] 130; Solenoid 131; Body
[13] 132; Fixture 133; Jam spring
[33] In order to achieve the above object, the fixing apparatus of an electrophotographic image forming apparatus according to the present invention develops an electrostatic latent image formed on a photosensitive member according to a control signal of a control apparatus, and transfers a developer forming an image onto printing paper. A phenomenon in which a developer of a transferred image is fixed to the printing paper by heat and pressure, and is a cylindrical roller provided on a main body of an electrophotographic image forming machine, and transferred to the printing paper by heat radiated from a heat source assembled therein. A fixing roller which melts the agent, a pressure roller which is installed on the lower side of the fixing roller so as to face the fixing roller, and presses the printing paper against the fixing roller to press the developer transferred to the printing paper; A pressing force for supporting the shaft of the pressure roller at both ends and the pressure roller presses the fixing roller Depending on the signal of the pressure means and the control device for generating is characterized in that it comprises a pressing force varying means for varying a pressing force of said pressing means at a predetermined cycle.
[34] Here, the pressing force varying means is located on the upper side of the axis of the pressure roller and one end is hinged to the main body of the electrophotographic image forming machine, the pressing plate for pressing the pressure roller shaft in the direction of gravity, and in contact with the upper surface of the other end of the pressure plate It is installed to rotate and the gear cam for swinging the pressure plate up and down, and the upper side of the gear cam and includes a solenoid for intermittent rotation of the gear cam according to the control signal of the control device.
[35] In addition, the gear cam preferably includes a gear portion having a gear tooth engaged with the fixing gear formed at one end of the fixing roller, and a cam portion having a polygonal shape extending in parallel with the gear portion.
[36] In addition, a portion of the gear tooth formed is removed, the gear body of the side of the removed portion is characterized in that the weight for rotating the gear cam is formed.
[37] Hereinafter, an embodiment of a fixing apparatus for an electrophotographic image forming apparatus according to the present invention will be described with reference to the accompanying drawings.
[38] 2 and 3, the fixing apparatus 100 of the electrophotographic image forming apparatus includes a fixing roller 101, a pressing roller 103, a pressing means 110, and a pressing force varying means.
[39] The fixing roller 101 is a cylindrical roller provided in the main body 104 of the electrophotographic image forming machine, and a heat source such as a halogen lamp is assembled therein. The fixing roller 101 is formed of a material having good thermal conductivity, and melts a developer that is transferred to the printing paper 1 with heat radiated from a heat source to form an image.
[40] In addition, one side of the fixing roller 101 is coaxially coupled to the fixing gear 102 that can transmit the rotational movement of the fixing roller 101.
[41] The pressing roller 103 is installed to rotate opposite to the fixing roller 101 at the lower side of the fixing roller 101, and both ends of the pressing roller shaft 103a are supported upward by the pressing means 110. The developer transferred to the printing paper 1 passing between the fixing roller 101 and the pressing roller 103 is pressed by the pressing force of the pressing means 110.
[42] The pressurizing means 110 supports both ends of the pressurizing roller shaft 103a upward so that the pressurizing roller 103 presses the fixing roller 101 to generate a pressing force. The elastic member 112 and the housing 111 Is done.
[43] The elastic member 112 is preferably a compression spring to elastically support the pressure roller shaft (103a).
[44] The housing 111 has an elastic member 112 provided therein and is installed in the main body 104 of the electrophotographic image forming apparatus.
[45] The pressing force varying means varies the pressing force of the pressing means 110 according to a control signal of the control device at a predetermined cycle, and includes a pressing plate 121, a gear cam 124, and a solenoid 130.
[46] The pressure plate 121 is positioned so as not to interfere with the pressure roller 103 and to contact both ends of the pressure roller shaft 103a from above, and one end thereof is hinged to the main body 104 of the electrophotographic image forming machine. It is installed so that it can turn around 121a).
[47] The gear cam 124 has a shape in which a gear and a polygonal cam are superimposed, and the gear part 122 having the gear tooth is engaged with the fixing gear 102 assembled at one end of the fixing roller 101. The cam part 123 formed in the shape is in contact with the other end upper side of the pressing plate 121.
[48] Gear portion 122 is formed so that a portion of the gear teeth are removed so that the gear 122 does not engage or interfere with the fixing gear 102 engaged in the portion (122a). The removal range of the gear portion 122 is a minimum range in which the fixing gear 101 and the gear portion 122 do not interfere when the gear cam 124 is fixed by the solenoid 130.
[49] In addition, the weight 125 that can overcome the pressing force of the elastic member 112 by its own weight on the side of the gear tooth removal portion 122a of the gear 122 and rotate the gear cam 124 in the direction of gravity by a predetermined angle. ) Is attached. Here, the predetermined angle is an angle at which the gear cam 125 rotates to be engaged with the fixing gear 102 outside the portion 122a from which the gear value of the gear portion 122 is removed.
[50] The cam part 123 is a polygonal side 123a and a vertex 123b alternately contact with the pressure plate 121 as the gear part 122 rotates so that the pressing force applied to the fixing roller 101 changes periodically. The polygon is determined in consideration of the elastic force and the variable period of the elastic member 112. In this embodiment, a polygon of a polygon is used for the cam portion 123.
[51] The solenoid 130 is to prevent the gear cam 124 from rotating by the weight 125 by fixing the gear portion 122 of the gear cam 124, the body 131 and the fixture 132 and the locking A spring 133.
[52] The body 131 has a solenoid coil assembled therein and pulls the fixture 132 according to the signal of the control device.
[53] The fixture 132 is installed at the lower end of the body 131 as a point of support, one end is provided with a locking step (132a) for fixing the gear teeth of the gear 122. In addition, a locking spring 133 is assembled to the other end 132b of the fixture 132.
[54] The engaging spring 133 is a compression spring, one end of which is fixed to the body 131 and the other end of which is assembled to the other end of the fixture 132b, such that the fixture 132 fixes the gear portion 122 of the gear cam 124.
[55] Hereinafter, the operation of the fixing apparatus of the electrophotographic image forming apparatus having the above configuration will be described with reference to FIGS. 2 to 4.
[56] When the control device recognizes printing of a thick printing paper 1 such as an envelope by a sensor (not shown) installed in the paper feeder or a user's selection, the control unit sends an operation signal to the solenoid 130.
[57] When the solenoid 130 operates, the fastener 132 moves upward, and the locking jaw 132a of the fastener is removed from the gear teeth of the gear unit 122. When the catching jaw 132a of the fixture is removed from the gear tooth, the gear portion 122 rotates in the gravity direction by the weight 125 so that the gear portion of the gear portion 122 and the fixing gear 102 mesh with the gear portion 122. ) Will begin to rotate. When the gear part 122 rotates, the polygonal cam part 123 integrally formed coaxially with the gear part 122 rotates together, such that the pressure plate 121 swings up and down about the hinge axis 121a. In other words, when the vertex 123b of the polygon is in contact with the pressure plate 121, the pressure plate 121 is pressed downward, and when the sides 123a of the polygon are in contact again, the pressure plate 121 is returned to its original position. When the gear cam 124 continues to rotate, the vertical motion of the pressure plate 121 continues.
[58] Therefore, when the polygonal edge 123a of the cam portion 123 presses the pressure plate 121, the same pressing force as that for printing normal paper is applied to the fixing roller 101, and the polygonal vertex 123b of the cam portion 123 is applied. When the pressing plate 121 is pressed, the pressure applied to the fixing roller 101 is reduced because the elastic member 112 is compressed in the gravity direction. That is, the pressing force applied to the fixing roller 101 by the pressing roller 103 changes periodically in the range between the pressing force suitable for general paper and the pressing force lower than this pressing force as the gear cam 124 rotates. During printing, the overall pressing force applied to the fixing roller 101 is reduced to prevent wrinkles in the envelope.
[59] When printing plain paper, the control device stops the operation of the solenoid 130. When the operation of the solenoid 130 is stopped, the fixture 132 is moved downward by the locking spring 133 so that the locking jaw 132a is caught by the gear teeth of the gear unit 122.
[60] Subsequently, the gear cam 124 rotates in conjunction with the rotation of the fixing gear 102, and then the gear cam 124 stops rotating when the gear tooth removal portion 122a comes in a position to engage with the fixing gear 102.
[61] At this time, the polygon of the cam portion 123 of the gear cam 124 is because the side 123a is in contact with the pressure plate 121, the pressure plate 121 does not press the elastic member 112, the fixing roller 101 and the pressure roller Between 103, an appropriate pressing force is applied to general paper.
[62] Therefore, the fixing apparatus 100 of the electrophotographic image forming apparatus according to the present invention uses the solenoid 130 for controlling only the fastener 132 for controlling the gear cam 124 and the fixing roller 101 and the pressure roller 103. Since the pressing force, i.e., the fixing pressure applied between the two parts, can be varied, a small amount of solenoid can be used, and wrinkles do not occur even when printing the envelope.
[63] As described above, according to the fixing apparatus of the electrophotographic image forming apparatus according to the present invention, by using the solenoid to control the gear cam that changes the fixing pressure, it is possible to use a small capacity solenoid. Wrinkles will not occur.
[64] In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. will be.

权利要求:
Claims (4)
[1" claim-type="Currently amended] After developing the electrostatic latent image formed on the photosensitive member in accordance with the control signal of the control device to transfer the developer forming the image to the printing paper, and to fix the developer of the transferred image on the printing paper with heat and pressure,
A fixing roller which is a cylindrical roller provided in a main body of an electrophotographic image forming machine, and which fuses the developer transferred to the printing paper with heat radiated from a heat source assembled therein;
A pressure roller which is installed on the lower side of the fixing roller so as to face the fixing roller and presses the printing paper against the fixing roller to press the developer transferred to the printing paper;
Pressing means for supporting the shafts of the pressing rollers at both ends and generating pressing force for the pressing rollers to press the fixing rollers;
And a pressing force varying means for varying the pressing force of the pressing means at predetermined intervals in response to a signal from the control device.
[2" claim-type="Currently amended] According to claim 1, wherein the pressing force variable means,
A pressing plate positioned above the shaft of the pressing roller and one end of which is hinged to the main body of the electrophotographic image forming machine, and presses the pressing roller shaft in a gravity direction;
A gear cam installed to rotate in contact with the upper surface of the other end of the pressure plate and to swing the pressure plate up and down; And
And a solenoid disposed on an upper side of the gear cam and controlling the rotation of the gear cam according to a control signal of the control device.
[3" claim-type="Currently amended] The method of claim 2, wherein the gear cam,
A gear part having gear teeth engaged with the fixing gear formed at one end of the fixing roller; And
And a polygonal cam portion extending from a side surface of the gear portion and formed parallel to the gear portion.
[4" claim-type="Currently amended] The method of claim 3, wherein the gear unit,
A portion of the formed gear tooth is removed, and a weight is formed in the gear portion body on the side of the removed portion.

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同族专利:

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公开号 | 公开日

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KR100423479B1|2004-03-18|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
2001-11-27|Application filed by 삼성전자주식회사

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2001-11-27|Priority to KR10-2001-0074153A

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2003-06-02|Publication of KR20030043135A

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2004-03-18|Application granted

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2004-03-18|Publication of KR100423479B1

优先权:

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申请号 | 申请日 | 专利标题

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KR10-2001-0074153A|KR100423479B1|2001-11-27|2001-11-27|Fix apparatus of an electric-photograpic printer|